1. Field of the Invention
The present invention relates to a stereo optical module and a stereo camera which can be mounted in a mobile body such as a vehicle, a marine vessel, an aircraft or a robot, or a non-mobile body such as a monitoring camera system.
2. Description of the Related Art
There has conventionally been utilized a stereo optical module which is connected with an imaging optical system of an imaging device to receive light from the same object at two distanced positions, and leads each light to an optical system of the imaging device to enable imaging (stereo shooting) of a stereo image, and various kinds of configurations of such a stereo optical module have been proposed.
For example, there has been proposed a stereo optical module which has a pattern projecting section which projects a predetermined pattern onto an object (see, e.g., Jpn. Pat. Appln. KOKAI Publication No. 2000-236332) or a stereo optical module in which a cylindrical lens or a wide-angle conversion lens is detachably set on a front surface thereof (see, e.g., Jpn. Pat. Appln. KOKAI Publication No. 327042-1997). Further, an endoscope which uses an image guide to obtain a binocular vision (see, e.g., Jpn. Pat. Appln. KOKAI Publication No. 016812-1992). Furthermore, a mirror configuration of a stereo optical module is disclosed in, e.g., Jpn. UM Appln. KOKAI Publication No. 112426-1978. Moreover, a trinocular stereo adapter has been also proposed (see, e.g., Jpn. Pat. Appln KOKAI Publication No. 2001-305682).
Additionally, in a conventional rain drop sensor proposed by Denso Corporation, light is projected from an infrared light or visible light emitting diode (a light projecting LED) 75 toward a glass block 74 appressed against a window glass 73 as shown in FIG. 26, for example. This light is concentrated by a light projecting lens 76, and reflected light of this concentrated light ray on a glass outer surface is led to a light receiving lens 78 by using a reflecting mirror 77 or the like. Then, the led light is concentrated by the light receiving lens 78, and this concentrated light ray is detected by a light receiving sensor 79 such as a photodiode. At this time, when rain drops have adhered to the window glass 73, light is scattered so that the light quantity varies, and hence the quantity of rain drops can be measured.